A small amount of an agricultural product got into the water and contaminated the system, officials said.

Residents who receive water from the system are asked not to use it at all. Even boiling it will not make it safe, authorities said. Residents aren't to use it in any capacity, nor should they give it to animals.

The system is being flushed and tested, authorities said.

The warning was first issued Monday. No illness have been reported, but authorities said anyone who experiences unusual physical symptoms should call the doctor.

The Obama administration will unveil a major climate change plan Monday aimed at a large reduction in greenhouse gas emissions from the nation's coal-burning power plants, a senior administration official told CNN.